Peatlands are considered degraded when they’ve been drained or subjected to altered water flow but have not been completely converted for other land uses. In this degraded state, the carbon stored in plant material buried in peat soil is released into the atmosphere. Dried peat is also susceptible to ground fires, releasing large amounts of stored carbon in short order.
Degraded peatlands are responsible for a large portion of carbon emissions from natural systems. Peat soils can be restored, however, to prevent the further breakdown of stored plant material and to capture new plant debris from vegetation growing aboveground. The primary method of restoration involves “re-wetting” or restoring the natural flow of water and soil saturation.
Around the globe, 46 million hectares of peatlands are in a degraded state and emitting greenhouse gases into the atmosphere. That’s an area slightly larger than the state of California.
Peatland restoration would prevent the release of 394 million tonnes of carbon dioxide equivalent per year (MtCO2e/year). That’s comparable to the emissions from 84 million passenger vehicles per year.
The primary challenge to peatland restoration is economic. Altering drainage patterns and local hydrogeography can be costly. We estimate that only 18 percent of the total mitigation potential for peatland restoration can currently be implemented at a low cost ($10 per tonne of CO2e per year).
Peatlands are rare, covering only about 3 percent of the Earth’s surface. Yet they provide important habitat for many species. Peatlands in Indonesia, for instance, provide prime habitat for orangutans. Restoration efforts will also have important benefits for biodiversity. Despite the economic hurdles, the technical capacity for restoring peatlands already exists and could be implemented immediately, especially in lower-cost regions.
Spotlight: Pocosin Lakes National Wildlife Refuge
The Pocosin Lakes National Wildlife Refuge spans 110,000 acres of North Carolina and is an important stopover point for migrating snow geese and tundra swans. But prior to becoming a refuge in 1991, many of the region’s peat soils were ditched and drained for development. The degraded peat soils dried out, releasing stored carbon into the atmosphere. The dried peat also spawned large wildfires in 1985 and 2008.
Since the Refuge was established, the U.S. Fish and Wildlife Service and partners have been working to reestablish the natural hydrology of the Pocosin Lakes region. The project involves installing levees and water control structures to stop the drainage of water from the soil, while still allowing soil moisture to fluctuate naturally as a result of rainfall and evaporation.
Conservancy staff and other partners are also comparing carbon emissions in restored and unrestored areas of the refuge, collecting information that will support peatland restoration efforts elsewhere in the world.
This pathway will be most important in Indonesia, which has the largest total area of degraded peat. Restoration could also be important in regions such as China, Finland and Russia, which have the largest area of degraded peat in the temperate region.